// 声明变量
let a;
let b, c, d;
let e = 100;
let f = 100, g = 'asd', h = [];

// # 1.变量不能重复声明
// let a = 100; //Could not establish connection. Receiving end does not exist.

// # 2.块级作用域
// if else for while
{
  let girl = 'lucy';
}
// console.log(girl); //girl is not defined

// # 3.不存在变量提升
// console.log(song); // Cannot access 'song' before initialization
let song = 'music';

// # 4.不影响作用域链
{
  let person = 'luck';
  function fn() {
    console.log(person); //luck
  }
  fn();
}

